Patent Document 1 discloses a kind of the actuator. A shaft, a motor, a circuit board and a gear mechanism are accommodated in a case. A part of the shaft protrudes outside the case. At least a part of a circuit configured to drive the motor is mounted on the circuit board. A driving force of the motor is transmitted to the shaft by the gear mechanism and the shaft is displaced in an axis direction thereof. A tip of the shaft positioned outside the case is coupled to a part of a lighting device mounted to a vehicle. As the shaft is displaced, a direction of an optical axis of an optical system included in the lighting device is changed in a predetermined direction.